Refrigeration



Dec. 3, 1935. c. e. MUNTERS REFRIGERATION Original Filed Feb. 9, 1935 II VI INVENTOR.

wwm 4 ATTORNEY.

UNITED STATES PATENT OFFICE REFRIGERATION Carl Georg Mnnters, Stockholm, Sweden, as-

signor, by mesne assignments, to Serve], Inc., Dover, DeL, acorporation of Delaware Original application February 9, 1933, Serial No. 655,881. Divided and this application July 18,

In Germany 1934, Serial No. 735,777.

My invention relates to refrigeration and more particularly to automatic control or regulation of intermittent absorption refrigeration apparatus. This application is a division of my application Serial No. 655;881. I

It is an object of my invention to provide automatic control or regulation of flow of fluid in an absorption refrigeration system without the use of valves or other mechanical moving parts.

Another object is to automatically control the operation of a vaporization-condensation element or fluid heat transfer circuit without the use of mechanical moving parts.

A further object is to provide an efficient arrangement for cooling a generator-absorber of an intermittent refrigeration system only during the absorption periods and which requires no valves or other mechanical moving parts.

The above objects are attained, in accordance with my invention, by controlling circulation of fluid responsive to heat. This I accomplish by elevating or preventing a normally downward flow of liquid responsive to heat by vapor liquid lift action.

The nature of my invention, together with the objects and advantages thereof, will be more fully understood upon consideration of the following description and accompanying drawing forming part of this specification and of which:

The figure shows schematically an intermittent absorption refrigeration apparatus embodying my invention.

Referring to the drawing, a generator-absorber Ill comprises an upright cylindrical vessel through which extends a heating flue II. A gas burner l2, provided with a suitable control valve I3, is aranged so that, when the burner is lighted, the

flame projects upwardly into the lower end of the flue H. The upper end of the generator I is connected by means of a conduit l4 to an aircooled condenser l5, and the latter is connected by means of a conduit IE to an evaporator I I. The generator I0 contains a solution of refrigerant in an absorbent, for instance, a water solution of ammonia.

In operation, the generator-absorber I0 is alternately heated, as by the burner l2, and cooled, as by'the means hereinafter described. The periodic heating of the system may be accomplished automatically. During the heating periods, ammonia vapor is expelled fromsolution in the generator-absorber, condensed to liquid in the condenser l5, and accumulated in the evaporator I'I. During the cooling or absorption periods, the ammonia evaporates in the evap- 7 Claims. (01. 62-118) orator l-l, producing a cooling or refrigerating effect. The vapor from the evaporator l1 flows through conduit I 6, condenser l5, and the conduit l4 to the generator-absorber In, Where it is absorbed into the solution from which it was 5 previously expelled. It will be understood that refrigeration systems of this type are known in the art and the system illustrated serves only the purpose of explanation and constitutes no limitation with; respect to the present invention 1 which may be embodied in any refrigeration system of the absorption type.

For cooling the generator-absorber I0, I provide a fluid heat transfer circuit embodying my invention. Around the generator-absorber is located, in thermal conductive relation therewith, a pipe coil l8,.which may be referred to as a cooling coil and is adapted to conduct-cooling liquid in thermal exchange relation with the generator-absorber as hereinafter described. 0

The upper end I3 of the cooling coil I8 is connected to a second air-cooled condenser 20. As

illustrated, the condensers I5 and may be arranged adjacent each other and provided with common heat radiation fins. The condenser 20 2 is connected by means of a conduit 2| to the upper part of a first vessel 22 which may be referred to as a collecting vessel. At a level below that of the collecting vessel 22 is located a second vessel 25 which may be referred to as a pressure vessel. The lower part of the upper vessel 22 is connected to the lower part of the lower vessel 25 by means of a conduit 28. As shown, the conduit 28 is connected at its upper end to the bottom of the upper vessel 22, and extends downwardly into the lower vessel 25, terminating in the lower part thereof. A vessel 23 and a conduit 24 are connected and arranged to form a U-tube liquid trap of which a narrow leg is formed by the conduit 24 and an enlarged leg is formed by 40 the vessel 23. The narrow leg opens at its upper end within the pressure vessel 25 at a level above that of the lower end of conduit 28. The upper end of vessel 23, or the enlarged leg of the liquid trap, is closed, and an overflow connection from the upper part .of vessel 23 to the lower end of the cooling coil l8v is provided by a conduit 21, of which the upper end opens within the upper part of vessel 23 and the lower end is connected to the lowerend of the cooling coil 18. The circuit comprising the cooling coil It, the condenser 20, the upper vessel 22, the lower vessel 25, and the U-tube liquid trap, together with the interconnecting conduits is. partially filled with a suitable volatile cooling liquid, preferably 5 one having a low vapor pressure at the normal room temperature as, for instance, benzol, pentane, or the like. The conduit l4 for conducting vapor to and from the generator-absorber I0 is arranged in thermal exchange relation with the pressure vessel 25, for instance, by forming a portion of this conduit as a coil around the vessel, as illustrated.

In operation, assuming that heating of the generator-absorber III has been discontinued to instig'ate a refrigeration or absorption period, liquid which is now permitted, as hereinafter described, to enter the coil l8, vaporizes, the heat of vaporization being supplied by transfer from the generator-absorber to cool the latter. The vapor flows from the upper end IQ of the coil l8 into the condenser 20, in which latter it is condensed to liquid which drains through conduit 2| into the upper vessel 22. From the latter, the liquid descends by gravity through conduit 28 and the lower vessel 25 into the liquid trap comprising conduit 24 and the vessel 23. From the vessel 23, the liquid overflows into conduit 21 and returns therethrough to the cooling coil l8, thus completing the fluid circuitwhich is continuous during the refrigerating or absorption periods. A pressure equalizing conduit 26 is advantageously provided from the upper part of the vessel 22 to the upper part of the vessel 23 to prevent trapping of gas that would interfere with the above described circulation.

' When heat is again applied to the generatorabsorber ID to instigate an expulsion or heating period, vaporization of liquidin the coil l8 continues temporarily. However, hot vapor, ex-

pelled from solution in the generator l0, now

flows through the conduit H in thermal transfer relation with the pressure vessel 25. This causes heating of liquid in the vessel 25, and the resulting vapor accumulates in the upper part of the vessel, being trapped there by liquid in conduit 28 and liquid in the trap formed by conduit 24 and vessel 23. The accumulation of vapor forces liquid downwardly in conduit 24 and upwardly in conduit 28. When the liquid level in the pressure vessel 25 is forced below the upper end of conduit 24, delivery of liquid to the cooling coil l8, as above described, is terminated. The coil I8 is preferably of a minimum liquid storage capacity in order to maintain heat loss at the end of each cycle at a minimum. The liquid forced upwardly through conduit 28, in opposition to the previously described downward flow therethrough, is stored in the upper vessel 22 during the expulsion periods. Vapor which may escape by bubbling around the lowerend of conduit 28 as the liquid reaches this level, is condensed to liquid in the condenser 20 and drains back into the upper vessel 22.

When heating of the generator is again dis.- continued to instigate the next absorption period, the vapor in the pressure vessel 25 condenses to liquid, and the cycle, described above, is repeated.

Various changes and modifications within the scope of my invention will be apparent to those skilled in the art, wherefore my invention is not limited to that which is shown in the drawingor described in the specification, but only as indicated in the following claims.

What I claim is:

1. In an absorption refrigeration apparatus having alternate periods of vapor expulsion and absorption, means forming a circuitfor fluid including an upper vessel, a lower vessel, a conduit from said upper vessel to the lower part of said lower vessel whereby liquid may flow downwardly between said vessels during the absorpculation of fluid in said circuit during said expulsion periods. 10

,2. In an absorption refrigeration apparatus having alternate periods of vapor expulsion and absorption, means forming a circuit for fluid including a vessel, a descending conduit communicating at its lower end with thelower part of said 15 vessel whereby liquid may flow downwardly through said conduit and vessel during the absorption periods, and means for causing accumulation of trapped vapor in the upper part of said vessel during said expulsion periods to ele- 2 vate liquid from said vessel through said conduit in opposition to said downward flow of liquid, thereby terminating circulation of fluid in said circuit during said expulsion periods.

3. In an absorption refrigeration apparatus 25 having alternate periods of vapor expulsion and absorption, means forming a circuit for fluid including an upper vessel, a lower vessel, a conduit from said upper vessel to the lower part of said lower vessel whereby liquid may flow downwardly 30 between said vessels during the absorption periods, and means for heating said lower vessel to cause accumulation of trapped vapor in the upper part thereof during said expulsion periods to elevate liquid from said lower vessel through said 35 conduit to said upper vessel in opposition to said downward flow of liquid, thereby terminating circulation of fluid in said circuit during said expulsion periods.

4. In an absorption refrigeration apparatus 40 having alternate periods of vapor expulsion and absorption, means forming a circuit for fluid including a vessel, a descending conduit communicating at its lower end with the lower part of said vessel whereby liquid may flow downwardly through said conduit and vessel during the absorption periods, a further descending conduit including a liquid trap and having its upper end communicating with said vessel at a level above that of the lower end of said first conduit, and means for causing accumulation of vapor in the upper part of said vessel during said expulsion periods to elevate liquid from said vessel through said first conduit in opposition to said downward 55 flow of liquid, thereby terminating flow of liquid into said further descending conduit during said expulsion periods.

' 5. In an absorption refrigeration apparatus having alternate periods of vapor expulsion and absorption, a generator-absorber, a fluid heat transfer for cooling said generator-absorber and including an upper vessel, a lower vessel, a conduit from said upper vessel to the lower part of said lower vessel whereby liquid may flow downward- 65 ly between said vessels during the absorption periods, a cooling element connected to receive liquid from said lower vessel, a condenser connected to receive vapor from said cooling element and deliver liquid to said upper vessel, and means for 7 sorber, a condenser at a level above said generator-absorber, a rising conduit from said cooling element to said condenser, and a descending return conduit from said condenser to said cooling element forming a closed fluid circuit, a trap in said return conduit, and a conduit for conducting vapor from said generator-absorber extending in heat transfer relation with said trap.

7. In refrigeration apparatus of the intermittent absorption type including a'generator-absorber, an intermittent cooling system for said generator-absorber comprising means forming a closed fluid circuit having an upper condensing portion between two upright portions, one of said upright portions extending in heat transfer relation with said generator-absorber, a trap in the other of said upright portions, and means for conducting vapor iromsaid generator-absorber in 6 heat exchange relationwith said trap.

CARL (mono mm'rnns. 

